One of the most popular questions regarding gas grills is why did my control valve stop working? Grill valves, for the most part, are simple machines that do extremely simple tasks. The valve in a gas grill is comparable to a simple ball valve that can slide across an oval shaped opening, allowing for more flow. Inside the valve are notches and a spring that create the needed tension to feel correct for the person using the grill. Inside this valve is lubrication grease, needed to keep the valve well lubricated. Most of the time, the grease on the inside of the valve overheats, causing the grease to not properly lubricate the valve. If the grease inside the valve catches on fire, usually the valve will get slightly less smooth to operate, although this change is usually too small to notice. If noticeable, generally the problem is dirt or some other obstruction in the valve. If the control valve freezes or locks, it is because of an exuberant amount of friction between the moving parts inside the control. Turning the knob like this generally only leads to broken control knobs. Once broken, they can not be repaired, only replaced.
To replace the control valve in your gas grill, simply locate your grills manifold. This is easily accomplished by following the gas line, as the manifold is attached to it in any make or model of gas grill. The manifold is generally protected either with a spray on primer or galvanizer. Each type of grill has a different set up for control valves, and needs to be replaced.
When converting a grill between natural gas (NG) and liquid propane (LP), the orifices located in the valves need to be changed. The orifices for propane will be much smaller than natural gas, because LP is actually a liquid, with an incredibly low boil temperature.
Converting a barbecue grill from natural gas to propane or propane to natural gas is completed by changing the orifice on the valve. Propane orifices have a much smaller hole in them than natural gas orifices because liquid propane is a tighter gas. Propane is actually a liquid with a very low boiling temperature. When liquid propane boils it does the same thing water and other liquids do — it vaporizes and becomes a gaseous form of itself. Because propane is still very cold when it reaches a vaporization (boiling) point the gas is very tight and needs a smaller opening than natural gas.
Once control valves begin sticking, freezing, and locking into place, little to nothing can be done to remedy the problem short of replacing the part. Using quality replacement gas grill parts is very advantageous, as OEM parts are of better quality, they fit better, work better, and above all else, are safer for repairs. To help keep your control valves in the best operating condition, apply a spray degreaser on a regular basis to and around the valve. Never take the valve apart, as they are not designed to be taken apart and put back together.
Also, most control valves on grills can be adjusted. Removal of the knob will show whether your grill has adjustable handles. Valve handles will have a flat section, called a “D” due to the shape. When the valve stem splits, it is usually due to the knob being too tight, and weather and environment has caused it to become either brittle, or the plastic expanded and broke. Control valves will sometimes have a very small set screw inside the valve stem if it doesn’t have the “D” shape. Some grills allow for some minor changes to your grills controls to completely customize the cooking experience. Adjusting the handle will not only change the “high” setting, but will also change the “low” setting, and everything else in-between.
As a parting note, if a valve leaks at the manifold, repair by resealing the connection. If it is leaking from the body, it has to be replaced.